| 摘要 |
PROBLEM TO BE SOLVED: To evaluate an optical waveguide layer without specially attaching an optical element by forming an inclined optical waveguide layer whose film thickness is consecutively reduced at a fixed rate continuously to the optical waveguide layer and providing photodetector detecting emitted light from the inclined optical waveguide layer. SOLUTION: The optical waveguide layer 2a having the same film thickness is formed on a base plate 1a, and the inclined optical waveguide layer 2b whose film thickness is consecutively reduced at the fixed rate is foamed continuously to the layer 2a. Propagated light 101a propagated in the layer 2a is propagated in the layer 2b and emitted on the layer 2b as emitted light 102a by mode transformation and the change of a critical angle by an inclined part. The emitted light 102a is detected by the photodetector 6 and analyzed based on relation between a detection position and light intensity, so that the respective parameters of the thin film optical waveguide 51 are evaluated. Thus, the layer 2a is evaluated and the change of refractive index caused by secular change is also measured. |
